1. Field of the Invention
The present invention relates to a total environmentally-friendly trenchless repairing method, and more particularly, to a total environmentally-friendly trenchless repairing method that is capable of performing the sealing for a manhole, a pipeline, and a branch pipe and the repairing for a leaking portion thereon, without forming trenches.
2. Background of the Related Art
A variety of conventional methods for repairing damage portions in a sewage pipeline have been proposed.
Generally, a sewage pipeline, which is used in sewage facilities, is formed by connecting a plurality of pipes formed of a cast-iron pipe, a concrete pipe, a plastic pipe or the like and is buried under the ground to allow polluted sewage such as domestic sewage and industrial sewage to flow therealong. Thus, the sewage is collected to a sewage treatment plant and is purified and treated therein.
For the protection of the natural environment and the prevention of the environmental pollution, thus, careful attention should be paid to prevent the sewage from leaking before the sewage reaches the sewage treatment plant after drained from households, and furthermore to keep ground water or soil from being polluted by the sewage. Because of the aging of the concrete sewage pipeline buried underground, however, cracks or holes may be formed on the concrete sewage pipeline, and because of the stages on the sewage pipeline formed by the differential settlement of the ground and the jointing portion of the pipeline, gaps may be formed on the sewage pipeline, such that the domestic sewage and the industrial sewage may be introduced into the underground to cause the ground water or soil to be polluted. Reversely, clean ground water may be introduced into the sewage pipeline to cause the purification costs consumed in water quality environment offices of cities and provinces to be excessively increased, which generates the loss of national tax. In the rainy season, especially, the above-mentioned problems become serious. So as to prevent the ground water or soil from being polluted by the sewage discharged by the holes or damages formed on the sewage pipeline, accordingly, it is necessary to repair the damaged sewage pipeline. In the past, thus, digging in the ground is performed, and the damaged sewage pipeline is separated from the entire pipeline and is exchanged with new one. Filling in the ground is then carried out. In this case, however, a high cost of repair and time investment should be needed.
Recently, a variety of trenchless repairing methods for sewage pipelines have been developed and suggested by advanced countries, and further, many countries have turned their attention to severe damages like the pollution of the ground water and soil caused by the damages of the sewage pipelines, such that they become focused on the repairing of the damaged sewage pipelines. As examples of the conventional repairing methods for the damaged sewage pipelines, a water stop material-packing method, an epoxy application method, a reinforcement lining method, and a snap lock method have been introduced and applied.
First, the water stop material-packing method is developed in U.S.A., which is generally applicable for the repairing for a portion of pipeline into which water is invaded. According to this method, urethane or epoxy solution is injected on the damaged portion found through the water sealing checking to prevent the invasion of water from the outside. However, the repairing method is performed separately from reinforcing work, and therefore, the water stop material-packing method is not ideal at the time when the pipe is destroyed or the reinforcement for the connected portion of pipes is needed. In case where the formed crack has a length longer than a packer, further, it is impossible to perform the repairing at a time.
The epoxy application method is developed in Switzerland, which is generally applicable for the repairing of the cracked or damaged portion of the pipeline or the connected portions of the pipeline. According to the epoxy application method, obstacles are removed by using a cutter robot and a repairing portion is ground. Next, the ground portion is completely dried by a heat gun, after which an epoxy resin is applied to the dried portion, which requires a relatively long cure time. Therefore, the epoxy application method has some disadvantages in that the working cost is very high, and the period of cure time is very long.
The reinforcement lining method is one of the repairing methods most widely used in recent days, which is generally applicable for the repairing for a portion on which leakage occurs due to the cracks, damages and stages of joints of the pipeline. According to the reinforcement lining method, it is checked whether an obstacle exists on the damaged portion of the pipeline, after which the obstacle is completely removed by means of high pressure jet cleaning. Next, a glass fiber felt which is made by impregnating resin into glass fiber is mounted on a packer and is moved to a repairing portion. The glass fiber felt is then compressed onto the portion by means of compressed air. The reinforcement lining method is performed just to reinforce the pipeline, but it is impossible to stop the invasion of water into the pipeline.
The snap lock method is developed in Japan, which is applicable to the repairing for a portion where no protruded crack is formed on a pipeline or for a portion where leakage occurs. According to the snap lock method, a rubber tube (or rubber sleeve) having both ends on which the water stop rubber is mounted is attached to a stainless sleeve, the water stop rubber being expanded up to 5 times to 10 times in volume when contacted with water. The stainless sleeve is brought into close contact with a damaged portion on the pipeline, such that the leaking water comes into contact with the water stop rubber to permit the water stop rubber to be expanded in volume, thereby blocking the leaking sewage. In the snap lock method, as the repairing material is just mounted, the repairing process is completed, thereby providing some advantages in that the repairing work is very simple and the repairing time is short, but because of the formation of the stage between the internal face of the sewage pipeline and the section of the water stop rubber mounted on the internal face of the sewage pipeline, the sewage flows along the repaired portion after the repairing of the damaged pipeline to cause foreign matters to be accumulated on the formed stage.
The variety of conventional pipeline repairing methods, which have been introduced up to now as mentioned above, have some advantages and disadvantages according to the respective methods, and are largely divided into water stop methods wherein the leakage or the invasion of water stops and reinforcement methods wherein the damaged pipeline is repaired. However, the conventional pipeline repairing methods do not have any plan to prevent the leakage and the invasion of water caused by the damages occurring after the damaged pipeline has been repaired. Moreover, after the water stop method is applied, if the invasion of water or the leakage happens again, the existing reinforcement sheet should be removed to perform the repairing work again.
According to the conventional repairing methods, additionally, a tube is inserted into the interior of the damaged pipeline when the sewage pipeline is repaired, but in this case, the diameter of the pipeline is reduced. Thus, the repairing appears completed when seen from the outside, but the sewage pipeline is decreased in diameter to cause an amount of water discharged to be reduced. The discharging is not gently performed within a given time period, and as a result, a serious problem occurs in which said sewage overflows toward the outside of the pipeline from the upper side of the pipeline.